MANUAL TEST FUNCTIONS
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FDR Frequency Domain Reflectometer
The FDR (Frequency Domain Reflectometer) functions very similarly to a TDR (Time Domain
Reflectometer), however the FDR function provides similar results based on a different physics
principal.
To provide the best comparison of multiple pairs, the TALAN provides the ability to plot
multiple FDR traces on the same display.
The Distance and Gain can be adjusted using the on-screen controls. You must specify the
Measurement Units, the Velocity Coefficient, Gain and Distance, but you do NOT specify a pulse
width (as required with a TDR).
To get the range to any point simply tap on the screen and a blue vertical line will indicate the
range.
Furthermore, multiple FDR traces can be plotted on the same graph. In the example shown
below, all pair combinations were automatically acquired, however, only the main pairs are
being displayed. This is accomplished by tapping the desired pair for display using the stylus. In
this example, pair 4:5 is the main pair (shown in red) and is connected to the phone switch;
however pairs 1:2, 3:6, and 7:8 are not connected to the switch. These unused pairs are
terminated at the patch panel before the switch with a slightly shorter cable length.
Furthermore, the switch is located 169 ft from the TALAN, and the few spikes at very short
range are showing the short cable that is connected from the TALAN to the wall jack.
